This invention relates generally to an apparatus for indicating when the socket of a quick-disconnect coupling may have been connected with a plug and more specifically to an indicating member which is connected with the plug and must be broken before a socket can be connected with the plug.
Various types of seals have commonly been utilized in association with meters and containers to indicate when they have been opened. A locking seal which is utilized in association with luggage tags is disclosed in U.S. Pat. No. 2,511,751. This locking seal includes a plurality of internal prongs which are enclosed by a cover and engage an annular shoulder on a male member to interconnect portions of a luggage tag. The internal prongs are formed separately from the cover which is of a relatively strong construction and would not be readily broken by tampering with the seal.
A sealing cap having internal prongs to engage an annular groove at one end of a bolt is disclosed in U.S. Pat. No. 2,103,743. The cap has a cover formed of frangible material. A separate spider having retaining fingers is mounted inside the cap to engage the annular groove in the outer end of the bolt. Other known sealing arrangements are disclosed in U.S. Pat. Nos. 1,581,901; 1,582,444; and 3,709,261.